Neil: Then you should definitely go on Space
Mountain. It's a must. And the railroad
and Matterhorn are pretty fun as well.

Meaning: While "must"
is normally used in English as modal, it can be used as a noun meaning
something that is indispensable or required.
However, while "must"
usually has a formal meaning when used as a modal, it's often used as a noun in
informal situations, when someone is giving a suggestion of something that is
worth doing. In the example above, Neil
says that the ride Space Mountain is a must, meaning that Maria should make
sure to go on it. Usually, "must" is used as a noun in the
phrase "to be a must."

Here is another example:

Having
a car is a must if you hope to live
and work in Los Angeles. While the
public transportation is acceptable for visitors, it's usually not reliable
enough for everyday commuting.

Meaning: In this case, it's being suggested that a car is necessary
for those living and working in Los Angeles due to unreliable public
transportation.

This idiom is from LSI's new edition
of "Reading Horizons," which will be used in the Level 6 Reading
classes. For more information, please visit http://www.languagesystems.com/